Auto CPAP Woes

rusty_shackleford · Post by **rusty_shackleford** » Tue Sep 18, 2007 5:45 pm

Hello all, I've had a suspicion for awhile that my machine was mistaking my normal breathing patterns as hypopneas. Well, I now have confirmation. To test this I wore my mask for approximately an hour without falling asleep, I then took it off for the night. The next morning when I looked at the data, sure enough I had a hypopnea index of 1.9. Has anyone else experienced a similiar problem and or have any suggestions as to what I should do?

Sammy_J · Post by **Sammy_J** » Tue Sep 18, 2007 5:49 pm

Yes, it can't tell if you are a sleep or awake. To have an accurate hypopnea evaluation you need to have a PSG. So, looking at the data you won't be able to tell if you had an obstruction or a hypopnea.

rusty_shackleford · Post by **rusty_shackleford** » Tue Sep 18, 2007 6:09 pm

I have had in total 4 PSG's over the past 5 years. Initially CPAP therapy made my AHI and total arousals increased, but after having a UPPP with septoturbinoplasty the PSG's showed improvement. My problem is that I would like to be able to take advantage of my machines "Auto" functionality and ability to track data. However if the machine mistakes my normal breathing patterns for hypopneas than it leads me to believe that:

1. It is going to increase the pressure needlessly
2. The data I do receive is not going to be accurate

Sammy_J · Post by **Sammy_J** » Tue Sep 18, 2007 6:18 pm

When I am asleep, I find the scoring accurate. To me it makes no difference if it is a hypop or obstructive event. It's an event in any case. If I am dozing off or awake (have trouble falling asleep) then it may not be accurate. When using APAP mode I have tight ranges but I also use CPAP mode. In CPAP mode you will be able to see your events as well. However, your sleep doctor or DME should've set your low and high values for you already on your xpap based on your latest PSG.

Snoredog · Post by **Snoredog** » Tue Sep 18, 2007 6:27 pm

[quote="rusty_shackleford"]Hello all, I've had a suspicion for awhile that my machine was mistaking my normal breathing patterns as hypopneas. Well, I now have confirmation. To test this I wore my mask for approximately an hour without falling asleep, I then took it off for the night. The next morning when I looked at the data, sure enough I had a hypopnea index of 1.9. Has anyone else experienced a similiar problem and or have any suggestions as to what I should do?

rusty_shackleford · Post by **rusty_shackleford** » Tue Sep 18, 2007 8:12 pm

These are some of the results I received over a 4 month period that led me to believe that perhaps the "Auto" function wasn't working for me. I am just at a loss as far as what to do. I feel like a lot of the time I sleep better without CPAP. My last PSG concluded that at a pressure of 8 I had no apneas or hypopneas. Any recommendations would be greatly appreciated.

zorrro13 · Post by **zorrro13** » Tue Sep 18, 2007 8:56 pm

. Some machines have a manual one like the S8. Machines equipped with Auto:Ramp can also be used as a manual settling.

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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI, Hypopnea, auto[/quote]

Snoredog I have this feature on my s8. Should i be using it?

Snoredog · Post by **Snoredog** » Tue Sep 18, 2007 8:59 pm

keep in mind those report graphs are an average.

I would set your Maximum up to 15cm. As for the Minimum, it depends on what is important to you, 5 cm actually shows the lowest AHI but things are heading on the upside from there. So the next dip is 9.0 cm would be the next pressure. Then you can have some periods where you need up to 13 cm.

You can set the Auto:Min to 7 or 8 or even 9 if you want a lower AHI. I'd leave the Max at 15 so it can go up if needed. If you were on CPAP at 8 or 9.0 that event needing 13 cm would be just ignored.

Slinky · Post by **Slinky** » Wed Sep 19, 2007 8:53 am

Our breathing pattern when we are awake is distinctly different than our breathing pattern during sleep and even these smart CPAPs aren't accurate in discerning between the two so they combine what they are reading.

When awake, you sometimes sigh, sometimes hold your breath a bit to avoid a sneeze or whatever. You just can't compare the two: awake and asleep.